Hi again,
The easiest way to do this is by setting up a custom domain to your tenant and then configuring a Login Page Template:
https://auth0.com/docs/customize/login-pages/universal-login/customize-templates
Afterwards, you can add extra fields to the auth0 widget by configuring the Partials within the Prompts and adding an extra Name field which would then be processed in an action so that it’s added to the new user:
https://auth0.com/docs/customize/login-pages/universal-login/customize-signup-and-login-prompts
For documentation on how to add the field using the Classic Universal Login instead, without using a custom domain, you can use the following Knowledge Solution: